1. Technical Field
The present invention relates to a forming method and a formed article.
2. Related Art
When a three-dimensional object having a shape with a hollow space, an eaves-like shape, or the like is formed with metal, a casting method using a mold and a method of removing an unnecessarily part from a rectangular parallelepiped block by machining such as cutting or the like have been used in the related art. In the casting method, mold production is required and finish processing after casting is also required. Thus, a problem arises in that plural molds are required when the three-dimensional object has a shape with a hollow space. In the machining method, considerable man-hours are required for cutting. Accordingly, in these methods, there is a problem of requiring many man-hours and costs for forming.
In JP-A-2003-320595, there is disclosed a method of forming a three-dimensional object by three-dimensional forming in which processes of disposing a metal powder layer, sintering a portion of the metal powder layer, which becomes a main body portion (core for manufacturing a tire), by irradiation with laser light, disposing a metal powder layer on the sintered layer in a laminated manner, and sintering the layers are repeatedly performed. In the technique disclosed in JP-A-2003-320595, it is possible to obtain a three-dimensional object (core for manufacturing a tire) including a main body portion by sintering the entire main body portion and then removing metal powder which is not sintered in portions other than the main body portion (support portion) with few man-hours compared to the related art.
However, in the technique disclosed in JP-A-2003-320595, in the process of forming a three-dimensional object, the metal powder layer in a powder state is laminated in the portions other than the main body portion (support portion) to be sintered. Therefore, since the support portion does not have the same strength as the main body portion, the support portion cannot be handled in the same manner as the main body portion. For example, when a part of the support portion is caused to collapse (move) by vibration, impact or the like, there is a concern that the shape of the main body portion to be formed on the support portion may not be a desired shape. In addition, when the metal powder of the support portion after the entire main body portion is sintered is removed, for example, there is a concern that some of the metal powder of the support portion may adhere (remain) onto the surface of the main body portion by static electricity or the like. Accordingly, a forming method, which is simpler than the casting method and the machining method and is capable of more easily and accurately forming a three-dimensional object and more reliably removing the support portion, has been demanded.